The invention relates to the field of sports involving gliding over snow.
It relates more particularly to the devices used on skis and, in particular, downhill skis.
It refers more specifically to devices for raising bindings, making it possible to optimize the transmission of the bearing forces exerted by the skier toward the board.
In a known manner, boards for gliding and, in particular, downhill skis include safety bindings consisting of a stop which interacts with the toe of the boot and a heelpiece holding the rear of the boot.
It is already known to mount the binding elements on raising platforms, the aim of which is to elevate the boot above the board for gliding. This is particularly advantageous when the board for gliding has a relatively pronounced sidecut, and it is thus necessary to prevent the boot coming into contact with the snow when the board is inclined laterally.
Other raising platforms have already been proposed to provide a degree of unclamping of the ski. In this type of platform, the rigidity of the sole of the boot and that of the board are dissociated in such a manner that the behavior of the ski corresponds to the intrinsic properties of the board independent of that of the boot.
Other types of raising platform have also been proposed which, on the contrary, act as stiffener in order to increase further the rigidity and stiffness of the board, in particular in the underboot zone. One example of such a platform is, in particular, described in document FR 2 684 885, in which the various elements mounted on the platform interact with one another when a force is exerted vertically by the skier.
Another type of platform has also been proposed, such as that described in document FR 2 777 792. Such a platform is composed of a raising plate on which the elements of the binding are arranged. This raising plate rests on flexible strips which extend to the front and to the rear of the zone for mounting the binding, and bear on the upper face of the ski by means of shock-absorbing blocks.
On account of the flexibility of the longitudinal tongues, such a device does not make it possible to transmit sufficiently effective bearing forces, in particular when the skier exerts forces at the location of one of the elements of the binding. Moreover, the presence of elastomeric blocks tends to damp the behavior of the board overall, so such devices are intended more for relatively soft skis and, conversely, very dynamic skis, in particular those used in competition.
A problem which the invention proposes to solve is allowing a raising platform to modify the behavior of the board for gliding when the forces are exerted by the skier, while not increasing its stiffness in terms of flexing and thus allowing it to bend.
The invention thus relates to a device for raising at least one binding element used on a board for gliding, including:
a zone for mounting the binding, integral with the board for gliding;
a bearing zone, extending the mounting zone in the direction of the end of the board.
This device is defined in that the end of the bearing zone facing toward the end of the board is secured to the upper face of the board by attaching means in such a manner that the forces exerted at the location of the element of the binding are partially transmitted to the board at the location of said end of the bearing zone, and in that it also includes a transverse groove located between the mounting zone and the bearing zone so as to allow the deformation of this bearing zone when the board is bent.
In other words, the device according to the invention makes it possible to transfer a portion of the forces exerted by the skier in front of the stop of the binding or behind the heelpiece.
In this way, when the skier initiates a turn and exerts forces at the location of the front stop of the binding, a portion of these forces is exerted via the device according to the invention a few centimeters or even a few tens of centimeters further forward.
Under these conditions, the bearing forces are exerted in a longer zone of the underboot section, which allows an efficient turn initiation and better control through the turn.
Indeed, the platform according to the invention does not interfere with the behavior of the board when the latter bends, since the characteristic transverse groove allows the bearing zone of the platform to deform when the board flexes.
In a particular embodiment of the invention, the transverse groove may advantageously be filled with an elastic material so as to allow the return of the bearing zone into position when the cause of the bending disappears.
In other words, the presence of an elastic material makes the raising device and thus the entire board more dynamic by opposing flexing in the bearing zone.
Advantageously, in practice, the raising device may also comprise a block for receiving the other element of the binding. This block may be connected to the zone for mounting the binding via a linking pin.
Advantageously, in practice, this block may have the ability to slide longitudinally. In this case, the ability to offset the bearing forces further forward or further to the rear of the binding, without making the stiffness of the sole of the boot affect the stiffness of the board, is retained. In other words, a certain unclamping of the boot relative to the board is thus provided.
In another embodiment, the zone for mounting the binding extends in the opposite direction from the bearing zone and receives the other element of the binding.
In other words, the raising device therefore includes a platform which receives the two elements of the binding, filling in the gap between the boot and the upper face of the board.
Advantageously, in practice, the means for attaching the end of the bearing zone onto the upper face of the board allow a longitudinal displacement of said end when the board is significantly bent.
In other words, when the board is significantly bent, the end of the bearing zone may slide slightly relative to the upper face of the board in order to prevent longitudinal forces being exerted on the board.
Indeed, the attaching means have the essential function of transferring a portion of the vertical forces exerted by the skier and must not secure the raising device via two ends, at the risk of generating clamping of the board.
Advantageously, in practice, this ability of the end of the bearing zone to be displaced longitudinally may be obtained by interposing a layer of viscoelastic material between the upper face of the board and the end of the bearing zone.
In this case, this layer of viscoelastic material efficiently transmits forces which are exerted vertically, and works in shear when the bearing zone tends to be displaced longitudinally.
In practice, the lower face of the bearing zone is shaped so as to clear a free space between the bearing zone and the upper face of the board, between the end secured to the board and the mounting zone.
In other words, only the end of the bearing zone comes into contact with the board in order not to risk clamping the board and to push back as far as possible from the binding the zone in which the forces are transferred.
According to a particular embodiment, the bearing zone may have two arms extending in the longitudinal direction of the board, these arms being connected in the vicinity of the zone for mounting the binding and at the location of the means for attaching onto the board.
In this way, the transmission of forces in the vicinity of the lateral zones of the board, substantially in line with the edges, is promoted.